Category: Science

Revealing unexplored dopants in semiconducting materials

The advancement of transparent electronics, one of the most anticipated technological developments for the future, is currently inhibited by a shortage of high-performance p-type conductors. In materials, doping is the intentional introduction of impurities into an intrinsic semiconductor for the purpose of modulating its electrical and optical and structural properties. Recent demonstration of tin monoxide as …

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Emergence of Perovskite (MAPI) phases upon little compression

Perovskites are among the most promising and versatile class of candidate compounds for new or improved materials in energy applications, including photovoltaics, superconductivity, and lasing. With the general formula ABX3, the perovskite structure consists of corner-sharing BX6 octahedra forming a three-dimensional (3D) framework that provides room for the A units in the resulting cuboctahedral cavities. …

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Not all materials are metallic under pressure: tuning the gap !

Highly stable materials are usually wide-gap insulators, where covalency dominates the ionic exchange, such as in carbon (diamond), MgO, and LiH, to name a few.  In our latest work,  in collaboration with experimental teams in USA,  UK, and Japan we studied the enhanced stability of Sn3N4 to applied pressure and temperature. Our predicted phase transitions were confirmed by state-of-the-art Synchrotron X-ray diffraction and …

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Possible superconductivity in hydrogenated carbon nanostructures

In this work we present an application of density-functional theory for superconductors (SCDFT) to superconductivity in hydrogenated carbon nanotubes and fullerane (hydrogenated fullerene). We show that these systems are chemically similar to graphane (hydrogenated graphene) and like graphane, upon hole doping, develop a strong electron phonon coupling. This could lead to superconducting states with critical …

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Doping@HP the case of polyethylene: superconductivity!

High pressure is an exciting field that has evolved incredibly far since the pioneering work of Cailletet, Amagat and Bridgman. A substantial amount of research in the field of high pressure (post-Bridgman era) was triggered by the tantalizing idea of metalizing hydrogen (Wigner and Huntington transition) which dates back to the mid 30’s. The metalization …

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“Cold-Passivation” of Defects in Tin-Based Oxides

Our latest results arising from a collaborative work with experimental groups in École Polytechnique Fédérale de Lausanne (EPFL), Neuchâtel,  University of California Berkeley, National Institute of Advanced Industrial Science and Technology (AIST Japan) and the Institute for Nanotechnology, University of Twente, is published now in Journal of Physical Chemistry C  (link). In this work we …

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Crystal defects for qubits

We had the opportunity to attend the CECAM-Workshop “Crystal defects for qubits, single photon emitters and nanosensors” in Bremen (Germany), an interesting and forefront workshop in crystal defects for quibits. Since we all know, the leading contender is the nitrogen-vacancy center in diamond which may be considered as a robust quantum tool. Several quantum algorithms and …

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Structures of exohedrally decorated C60-Fullerenes

In our most recent publication we studied the exohedrally metal decorated carbon-fullerenes. These systems are a promising material for its good hydrogen adsorption (high concentrations and with optimal binding energies) properties. Since their geometry and type of coverage play a key role in determining the H2 adsorption mechanism, in this paper just accepted in Carbon …

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Searching hole-electron substitutional dopants for TCO technologies

The combination of optical transparency and high electrical conductivity enables transparent conductive oxide (TCO) materials to be used for a wide range of applications -from simple smart window coatings to OLEDs and futuristic see-through displays.  Doped tin-dioxide (SnO2) is an important semiconductor that is already used for these applications. However, in order to uncover the …

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Resolving the open controversies on the anomalous #superconducting trends in metastable phases of #Phosphorus

Among elemental compounds, the high-pressure superconducting phase diagram of phosphorus is one of the most complex. In this work, we measured electrical resistivity and performed ab initio superconductivity calculations in order to solve, for the first time the open controversies on the anomalous superconducting trends. Our work forms on a single picture a consistent scenario …

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